Welcome to BrainStuff, a production of I Heart Radio.

Hey Brain Stuff, Lauren Vogelbaum here.

When economic times are uncertain, people want to put their money in something solid.

That helps explain why 80% of all $100 bills in circulation

are now held outside of the United States.

That's up from only 30% back in 1980.

The steep rise in the number of $100 bills held overseas,

close to two C notes for every person on the planet,

is a signal that people around the world

recognize the US dollar as the de facto global currency. They have confidence that

if their local currency

for a rainy day, it's not only individuals who are saving American currency for a rainy day,

it's foreign governments too. The governments don't stockpile fiscal dollars in their central banks but they do buy

up loads of U.S. Treasury bonds and T bills which are valued in dollars.

As of January 2020, Japan and China each owned more than one trillion dollars in U.S. Treasury

securities, followed by the United Kingdom with $372 billion, and Brazil with $283 billion.

According to the International Monetary Fund,

more than 61% of the world's cash reserves are held in dollars.

The Bureau is in far second place at 20%.

When even an economic powerhouse like China holds a trillion US dollars in reserve,

that's a good sign that the dollar is still considered the mightiest of the global

currencies. But the dollar wasn't always the world's de facto currency. So what changed?

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